FRCA Notes

Cerebral Palsy

This topic was an SAQ in 2018 (79% pass rate), and the more recent BJA Education article raises suspicions it may reappear.

Resources

  • Cerebral palsy is defined by NICE as:

    • 'An umbrella term for a group of permanent movement and posture disorders that limit activity'

    ' The underlying cause is an acquired pathology within the developing brain, during the prenatal, neonatal or early infant period'

  • Prevalence 1.77 in 1,000 live births

Ante-natal (70 - 80%)

  • Prematurity <32 weeks gestation
  • Low birth weight <2.5kg
  • Multiple births
  • Intra-uterine TORCH infections: toxoplasmosis, varicella, rubella, cytomegalovirus, herpes
  • Foetal alcohol syndrome
  • Congenital metabolic syndrome
  • Low socioeconomic status
  • Maternal hyperthyroidism

Peri-natal (10%)

  • Birth complications:
    • Placental abruption
    • Uterine rupture
    • Pre-eclampsia
    • Hypoxic injury
  • Prolonged or obstructed labour

Post-natal (10%) [up to 2yrs into the post-natal period]

  • Neonatal jaundice/kernicterus
  • Neonatal sepsis
  • Hypoglycaemia
  • Events in the first two years of life:
    • Cerebral haemorrhage/infarction
    • Cerebral infection
    • Trauma
    • Seizures

  • Historically classified by motor type:
    • Spastic i.e. increased tone (85-90%)
    • Dyskinetic i.e. recurring involuntary uncontrolled movements (7%)
    • Ataxic i.e. hypotonia and loss of muscle coordination (4%)
  • Could be unilateral (hemiplegic), bilateral (diplegic) or quadriplegic

  • The Gross Motor Function Classification (GMFC) system is now widely used
    • It incorporates functional ability
    • It is age-specific
    • Graded from I (best) to V (worst)

Respiratory

Factor Anaesthetic relevance
Prematurity Chronic lung disease from infant respiratory distress syndrome
Repeated aspiration Chronic lung disease
Increase post-operative pulmonary complications
Consider ETT even for simple cases
Scoliosis Restrictive lung defect
Pulmonary hypertension
Respiratory muscle hypotonia Poor cough
Recurrent infections

Neurological

Factor Anaesthetic relevance
Learning difficulties/cognitive impairment (50%) Higher pre-operative anxiety
Consent/capacity issues
Communication difficulties (50%) due to:
Expressive language disorders
Motor problems affecting speech
Audio/visual impairment		 Difficulty communicating pain or anxiety
Consent/capacity issues
Epilepsy (33%) ANti-epileptic drugs can:
Induce/inhibit enzymes
Reduce MAC by 30%
Cause sedation & slower recovery from anaesthesia
Abnormal pain perception May be difficult to manage post-operative pain
Spasticity Difficult vascular access
Difficult positioning
Mental health issues Exacerbated by pain, insomnia, disturbance to routine

Gastrointestinal

Factor Anaesthetic relevance
Pseudo-bulbar palsy leading to drooling
Overactive salivary glands		 May already be taking anti-cholinergic medication
Consider anti-sialogogue if not
Impaired views at laryngoscopy
Gastro-oesophageal reflux Risk of aspiration at induction
RSI technique
Oesophageal dysmotility Aspiration pneumonia and poorly compliant chest
Nutritional issues Dehydration, anaemia, electrolyte imbalance
Chronic constipation (60%) Consider minimising opioid prescriptions

Renal

  • 60% of patients with CP are incontinent due to:
    • Neuropathic bladder
    • Immobility
    • Communication difficulties
  • Repeated urinary catheterisation and previous surgeries increase risk of latex allergy due to repeated exposure

Musculoskeletal

  • Polyfactorial low bone density
    • Non-ambulant (GMFCS IV and V)
    • Vitamin D deficiency
    • Other nutritional deficiencies
    • Reduced birth weight
    • Use of anti-epileptic drugs
  • Higher-than-expected blood loss can occur due to poor nutrition, use of AEDs and depletion of clotting factors
  • Thin skin, little subcutaneous fat and atrophied muscle increases risk of hypothermia and pressure injury

Analgesia

  • Simple analgesia
  • PPI's for GORD pain
  • Laxatives for constipation-related pain
  • Non-pharmacological methods
  • Surgical correction of flexion deformities and scoliosis
  • Manage hypertonia

Management of hypertonia

  • PT/OT
  • Baclofen | Diazepam | Gabapentin | Clonidine
  • IM injections: Botox A, phenol, ethanol
  • Surgical muscle or tendon lengthening procedures
  • Acute muscle spasm may be treated with 0.1mg/kg IV diazepam

Perioperative management of the patient with cerebral palsy


  • Higher-functioning children (GMFCS I or II) may be suitable for routine care
  • Children with more complex disease require:
    • High levels of communication within an MDT
    • Suitable pre-assessment
    • Investigations targeted to individual comorbidities and surgery

Optimisation

  • Managing anxiety including with non-pharmacological support
  • Optimising nutritional status
  • Optimising hydration status
  • Continuation of drug therapy in peri-operative period inc. AED
  • Commencement and maintenance of physiotherapy for contractures

  • Consider anti-sialogogue ± anxiolytic premedication

Monitoring and access

  • AAGBI monitoring

  • Often difficult IV access
  • Need to place and secure lines carefully with respect to limb contractures
  • May need to consider CVC, especially for major surgery

Anaesthetic technique

  • Propofol may be the induction agent of choice to reduce airway reactivity
  • Inhalational induction may well be needed due to difficulties with IV access

  • Caution with suxamethonium due to potential for extra-junctional nAChR proliferation
  • Tend to use non-depolarising agent instead

  • Potentially difficult airway and aspiration risk due to:
    • Copious secretions
    • Poor dentition
    • Temperomandibular spasticity
    • High incidence of GORD
  • Use an RSI technique

Analgesia

  • Use regional anaesthesia wherever possible, including wound infusion catheters
  • If having bilateral lower limb procedures e.g. osteotomies, consider neuraxial blockade
  • Simple analgesics
  • Caution with excessive long-acting opioids

Care bundle

  • Ensure meticulous positioning as higher risk due to reduced subcutaneous tissue and contractures
  • Maintenance of normothermia as at higher risk due to low body weight
  • At higher risk of excessive blood loss; consider cell salvage and TXA

  • May require a higher care area

  • Higher risk of post-operative pulmonary complications, owing to:
    • Poor cough
    • Reduced respiratory drive, especially if opioids used
    • Secretion retention
    • Basal atelectasis
  • Post-operative physiotherapy is important

  • Appropriate temperature monitoring and control is important, as hypothermia may induce spasms
  • May need PCA for more extensive or painful orthopaedic procedures